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• Active targeted aza-BODIPY conjugates are promising photosensitizers for melanoma. • Ex vivo biodistribution assay showed conjugates 1a and 1b accumulated in the tumour. • 1b was found to reduce tumour volume and growth suppression after PDT up to 12 days. Active targeting compound, a non-iodinated derivative of IK-IK-I 2 -azaBODIPY (1a) was previously reported to preferentially bind melanoma over healthy cells. In this study, we evaluate the photodynamic therapy (PDT) efficiency on melanoma cells of 1a , together with its reversed sequence compound KI-KI-I 2 -azaBODIPY (1b) and a non-targeted control I 2 -azaBODIPY-NH 2 (2). All three test compounds possess absorption wavelengths in the near-infrared (NIR) region (λ max between 678 and 687 nm) which alleviate melanin interference and allow deeper tissue penetration. In vitro studies revealed 1a and 1b are promising photosensitizers with enhanced singlet oxygen generation, have increased uptake by B16-F10 melanoma cells via clathrin-mediated endocytosis and good photocytotoxic efficacies. Ex vivo biodistribution assays showed both 1a and 1 b accumulated in the tumour. In B16-F10 tumour bearing-C57BL/6 mice, 10 mg/kg of 1b and light irradiation was found to reduce tumour volume by up to 23% at day-3. Doubling the dosage of 1b (20 mg/kg) enhanced the antitumour effect, showing 96% maximum tumour volume reduction at day-7 and tumour growth suppression for up to 12 days. [ABSTRACT FROM AUTHOR]

[Display omitted] • The first study of Coumarin-based, Tryptophan-containing polynorbornene (Poly-Cou-Trp). • A multifunctional fluorescent chemosensor with ON-OFF-ON response for Cu2+ and Arginine. • Developed colorimetric test strips for efficient detection of Cu2+ and Arginine levels. • The polymeric sensor exhibits high sensitivity, reproducibility, and a low detection limit. • Poly-Cou-Trp demonstrates low cytotoxicity across a range of tested cell lines. In this study, we synthesized a polymeric fluorescent chemosensor probe using Coumarin (Cou) and Tryptophan (Trp)-derived norbornene (NB) monomers through Ring Opening Metathesis Polymerization (ROMP). The combination of Cou and Trp influenced fluorescence selectivity and quenching efficiency. The NB-Cou-Trp monomer and the Poly-Cou-Trp polymer fluorescent probes exhibited multifunctional chemosensor properties, displaying fluorescence on-off-on characteristics. These probes selectively detected Cu2+ and Fe3+ ions, and subsequently, their Cu2+ complex showed selectivity for Arginine (Arg) in DMF solution. The detection limit (LOD) for Cu2+ was determined to be 0.232 µM for the monomer and 0.114 µM for the polymer. When complexed with Cu2+, the LOD for Arg was 0.233 µM for the monomer. In test strip form, this probe exhibited an on–off-on fluorescence phenomenon after adding metal and arginine, respectively, with colorimetric changes under different light lamp irradiations, allowing for discrimination of the presence of Cu2+ and Arg. Cell cytotoxicity tests in various cell types confirmed biocompatibility, suggesting potential for l-arginine biosensing detection in several fermented food products, diagnosis, prognosis, and treatment monitoring of many diseases, including cancer. [ABSTRACT FROM AUTHOR]

A new fluorometric sensor based on salicylideneaniline derivative for the detection of Cu2+ ion in aqueous media was developed and synthesized. The sensor showed strong absorption and fluorescence emission in an aqueous system through ESIPT and ICT characters. The greenish yellow fluorescence emission quenching and color change from bright yellow to pale yellow were observed after complexation with Cu2+ via the chelation-enhanced quenching (CHEQ) process. The sensor can recognize Cu2+ ion with high sensitivity and specificity over potential interfering ions as well as a low detection limit of 0.87 ppb, which was lower than the limit level concentration of Cu2+ in drinking water by the United States Environmental Protection Agency (U.S. EPA) and World Health Organization (WHO). The Job's plot, X-ray Absorption Spectroscopy (XAS), and 1H NMR illustrated the chelating mode between PS and Cu2+ ion in 1:1 stoichiometric complexation. The DFT calculations revealed ligand-to-metal charge transfer (LMCT) phenomena upon the Cu2+ binding of PS. Moreover, this fluorescence sensor was successfully employed for analyzing Cu2+ concentration in real water samples as well as living cells. [Display omitted] • Ultrasensitive fluorogenic chemosensor with a low detection limit of 0.87 ppb. • The detection mechanism relies on ESIPT and ICT process leading to fluorescence quenching. • 1:1 stoichiometric complexation of the sensor confirmed by Job's plot, 1H NMR titration, and the XAS analysis. • DFT calculations revealed ligand-to-metal charge transfer (LMCT) process upon the Cu2+ binding. [ABSTRACT FROM AUTHOR]

Abstract: A novel macromolecule based on 2-[3-(2-aminoethylthio)propylthio]ethanamine covalently bound to two 7-nitrobenzo-2-oxa-1,3-diazolyl moieties was prepared as a fluoroionophore and a chromophore for the selective optical detection of Hg2+. The sensor was prepared in two steps and its fluoroionophoric and chromophoric properties toward various transition metal, alkali, and alkali earth cations were investigated. Compound 4 selectively binds Hg2+, and the binding is indicated by both fluorescence quenching and a chromogenic change which can be detected by the naked eye. In an 80:20 acetonitrile/water solvent mixture, 4 acts as an ON–OFF fluorescence switch upon Hg2+ binding, exhibiting efficient quenching and a detection limit of 10−7 M or 20ppb. [Copyright &y& Elsevier]

Fluorescent probes sensitive to microenvironments have constantly been attractive, due to their significant benefits in monitoring changes in the pathophysiological microenvironment and their use in the early detection of associated disorders. In this work, we explored three new molecular rotors that could be potential candidates for detecting lipid droplets (LDs) in cancer cells based on coumarin derivatives connected with electron-donating polycyclic units including, tetraphenylethylene (LD-TPE), pyrene (LD-PYR), and 4,5-diphenylimidazole (LD-DIP). Gratifyingly, LD-PYR showed exceptional polarity and viscosity sensitivity and demonstrated bright fluorescence in highly viscous environments due to the suppression of the twisted intramolecular charge transfer (TICT) phenomenon and intramolecular rotation. Moreover, microenvironment-guided specific LD bioimaging by LD-PYR exhibited a reasonable ability to distinguish between cancer and noncancer cells. These data suggested that LD-PYR has interesting clinical diagnostic and microenvironment-related biological applications. [Display omitted] • Highly polarity and viscosity-sensitive fluorescence probes have been introduced. • LD-PYR probe shows bright fluorescence in a lipophilic environment due to TICT suppression. • LD-PYR demonstrates good biocompatibility in both cancer cell and normal cell lines. • LD-PYR can selectively image lipid droplet in cancer cells. [ABSTRACT FROM AUTHOR]

Abstract: A novel fluorometric sensor bearing three dansyl moieties based on tris[2-(2-aminoethylthio)ethyl]amine was prepared by a simple approach using a conventional two-step synthesis. The sensor exhibits highly Hg2+-selective ON–OFF fluorescence quenching behavior in aqueous acetonitrile solutions and is shown to discriminate various competing metal ions, particularly Cu2+, Ag+, and Pb2+ as well as Ca2+, Cd2+, Co2+, Fe3+, Mn2+, Na+, Ni2+, and Zn2+, with a detection limit of 1.15×10−7 M or 23ppb. [Copyright &y& Elsevier]

• Na0.5Bi2.5Nb2O9 nanosheets with exposed {001} facets have been synthesized. • Classical and microwave-assisted hydrothermal and molten-salt routes were used. • Superior photocatalytic efficiency, compared with a TiO2 degussa P25, was observed. • Photodegradation for both cationic and anionic dyes was enabled. • The prepared photocatalyst exhibited high stability and recyclability. The less investigated Bi layer-structured oxides, Na 0.5 Bi 2.5 Nb 2 O 9 , have been explored in this work. Its distinctive layered structure induces internal electric field, which is advantageous for charge separation and transfer. As a result, the compound is an effective photocatalyst. Such a property can be further enhanced by tuning the morphology. Although all samples show similar crystal structures and optical properties, a hydrothermal technique results in unique thin nanosheets while a microwave-assisted hydrothermal and a molten-salt technique yield irregular-shape nanoparticles and orthorhombic-shape microparticles, respectively. Among all samples, nanosheets exhibit the best Rhodamine B photodegradation. The outstanding performance is attributed to the nanosheet feature, which facilitates charge separation, and the highly exposed reactive {001} facet. Furthermore, the high efficiency, stability, and recyclability suggest it to be a potential candidate for other photocatalytic reactions and similar strategies could be used to design photocatalysts for green and sustainable solutions to environmental problems. A facile and efficient strategy to design high efficient photocatlayst with synergic effects of coexistence {001} exposed facet and internal electric field in Na 0.5 Bi 2.5 Nb 2 O 9 nanosheet is present. [Display omitted] [ABSTRACT FROM AUTHOR]